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The Association for the Scientific Study of Consciousness (ASSC) is a professional membership organization that aims to encourage research on consciousness in cognitive science, neuroscience, philosophy, and other relevant disciplines in the sciences and humanities, directed toward understanding the nature, function, and underlying mechanisms of consciousness.

The dentate gyrus is part of a brain region known as the hippocampus (part of the hippocampal formation). The dentate gyrus is thought to contribute to the formation of new episodic memories, the spontaneous exploration of novel environments, and other functions. It is notable as being one of a select few brain structures currently known to have significant rates of adult neurogenesis in many species of mammals, from rodents to primates (other sites include the subventricular zone of the striatum and cerebellum). However, whether neurogenesis exists in the adult human dentate gyrus is currently a matter of debate.

Etiocholanolone, also known as 5β-androsterone, as well as 3α-hydroxy-5β-androstan-17-one or etiocholan-3α-ol-17-one, is an etiocholane (5β-androstane) steroid as well as an endogenous 17-ketosteroid that is produced from the metabolism of testosterone. It causes fever, immunostimulation, and leukocytosis, and is used to evaluate adrenal cortex function, bone marrow performance, and in neoplastic disease to stimulate the immune system. Etiocholanolone is also known to be an inhibitory androstane neurosteroid, acting as a positive allosteric modulator of the GABAA receptor, and possesses anticonvulsant effects. The unnatural enantiomer of etiocholanolone is more potent as a positive allosteric modulator of GABAA receptors and as an anticonvulsant than the natural form.Etiocholanolone is produced from 5β-dihydrotestosterone, with 3α,5β-androstanediol as an intermediate.

The flocculus (Latin: tuft of wool, diminutive) is a small lobe of the cerebellum at the posterior border of the middle cerebellar peduncle anterior to the biventer lobule. Like other parts of the cerebellum, the flocculus is involved in motor control. It is an essential part of the vestibulo-ocular reflex, and aids in the learning of basic motor skills in the brain.

It is associated with the nodulus of the vermis; together, these two structures compose the vestibular part of the cerebellum.

At its base, the flocculus receives input from the inner ear's vestibular system and regulates balance. Many floccular projections connect to the motor nuclei involved in control of eye movement.

The name granule cell has been used for a number of different types of neuron whose only common feature is that they all have very small cell bodies. Granule cells are found within the granular layer of the cerebellum, the dentate gyrus of the hippocampus, the superficial layer of the dorsal cochlear nucleus, the olfactory bulb, and the cerebral cortex.

Cerebellar granule cells account for the majority of neurons in the human brain. These granule cells receive excitatory input from mossy fibers originating from pontine nuclei. Cerebellar granule cells project up through the Purkinje layer into the molecular layer where they branch out into parallel fibers that spread through Purkinje cell dendritic arbors. These parallel fibers form thousands of excitatory granule-cell–Purkinje-cell synapses onto the intermediate and distal dendrites of Purkinje cells using glutamate as a neurotransmitter.

Layer 4 granule cells of the cerebral cortex receive inputs from the thalamus and send projections to supragranular layers 2-3, but also to infragranular layers of the cerebral cortex.

Janette Atkinson, is a British psychologist and academic, specialising in the human development of vision and visual cognition. She was Professor of Psychology at University College London from 1993: she is now Emeritus Professor. She was also Co-Director of the Visual Development Unit at the Department of Psychology, University College London and the Department of Experimental Psychology, University of Oxford. She is a frequent collaborator with her husband Oliver Braddick.

The median eminence, part of the inferior boundary of the hypothalamus in the brain, is attached to the infundibulum. The median eminence is a small swelling on the tuber cinereum, posterior to and atop the pituitary stalk; it lies in the area roughly bounded on its posterolateral region by the cerebral peduncles, and on its anterolateral region by the optic chiasm.

As one of the seven areas of the brain devoid of a blood–brain barrier, the median eminence is a circumventricular organ having permeable capillaries. Its main function is as a gateway for release of hypothalamic hormones, although it does share contiguous perivascular spaces with the adjacent hypothalamic arcuate nucleus, indicating a potential sensory role.

In the hippocampus, the mossy fiber pathway consists of unmyelinated axons projecting from granule cells in the dentate gyrus that terminate on modulatory hilar mossy cells and in Cornu Ammonis area 3 (CA3), a region involved in encoding short-term memory. These axons were first described as mossy fibers by Santiago Ramón y Cajal as they displayed varicosities along their lengths that gave them a mossy appearance. The axons that make up the pathway emerge from the basal portions of the granule cells and pass through the hilus (or polymorphic cell layer) of the dentate gyrus before entering the stratum lucidum of CA3. Granule cell synapses tend to be glutamatergic (i.e. excitatory), though immunohistological data has indicated that some synapses contain neuropeptidergic elements including opiate peptides such as dynorphin and enkephalin. There is also evidence for co-localization of both GABAergic (i.e. inhibitory) and glutamatergic neurotransmitters within mossy fiber terminals. GABAergic and glutamatergic co-localization in mossy fiber boutons has been observed primarily in the developing hippocampus, but in adulthood, evidence suggests that mossy fiber synapses may alternate which neurotransmitter is released through activity-dependent regulation.

Nerve growth factor (NGF) is a neurotrophic factor and neuropeptide primarily involved in the regulation of growth, maintenance, proliferation, and survival of certain target neurons. It is perhaps the prototypical growth factor, in that it was one of the first to be described. Since it was first isolated by Nobel Laureates Rita Levi-Montalcini and Stanley Cohen in 1956, numerous biological processes involving NGF have been identified, two of them being the survival of pancreatic beta cells and the regulation of the immune system.

The oxytocin receptor, also known as OXTR, is a protein which functions as receptor for the hormone and neurotransmitter oxytocin. In humans, the oxytocin receptor is encoded by the OXTR gene which has been localized to human chromosome 3p25.

The pars compacta is a portion of the substantia nigra, located in the midbrain. It is formed by dopaminergic neurons and located medial to pars reticulata. Parkinson's disease is characterized by the death of dopaminergic neurons in this region.

Pyotr Kuzmich Anokhin (Russian: Пётр Кузьми́ч Ано́хин) (January 26, 1898 – March 5, 1974) was a Russian biologist and physiologist, author of Theory of functional systems and concept of systemogenesis. He made important contributions to cybernetics and psychophysiology. His pioneering concept on feedback was published in 1935.

The rectococcygeal muscles are two bands of smooth muscle tissue arising from the 2nd and 3rd coccygeal vertebrae, and passing downward and forward to blend with the rectal longitudinal smooth muscle fibers on the posterior wall of the anal canal.

Sensory processing is the process that organizes sensation from one’s own body and the environment, thus making it possible to use the body effectively within the environment. Specifically, it deals with how the brain processes multiple sensory modality inputs, such as proprioception, vision, auditory system, tactile, olfactory, vestibular system, interoception, and taste into usable functional outputs.

It has been believed for some time that inputs from different sensory organs are processed in different areas in the brain. The communication within and among these specialized areas of the brain is known as functional integration. Newer research has shown that these different regions of the brain may not be solely responsible for only one sensory modality, but could use multiple inputs to perceive what the body senses about its environment. Multisensory integration is necessary for almost every activity that we perform because the combination of multiple sensory inputs is essential for us to comprehend our surroundings.

The soma (pl. somata or somas), perikaryon (pl. perikarya), neurocyton, or cell body is the bulbous, non-process portion of a neuron or other brain cell type, containing the cell nucleus. The word 'soma' comes from the Greek 'σῶμα', meaning 'body'. Although it is often used to refer to neurons, it can also refer to other cell types as well, including astrocytes, oligodendrocytes, and microglia. There are many different specialized types of neurons, and their sizes vary from as small as about 5 micrometres to over 10 millimetre for some of the smallest and largest neurons of invertebrates, respectively.

The soma of a neuron (i.e., the main part of the neuron in which the dendrites branch off of) contains many organelles, including granules called Nissl granules, which are composed largely of rough endoplasmic reticulum and free polyribosomes. The cell nucleus is a key feature of the soma. The nucleus is the source of most of the RNA that is produced in neurons. In general, most proteins are produced from mRNAs that do not travel far from the cell nucleus. This creates a challenge for supplying new proteins to axon endings that can be a meter or more away from the soma. Axons contain microtubule-associated motor proteins that transport protein-containing vesicles between the soma and the synapses at the axon terminals. Such transport of molecules towards and away from the soma maintains critical cell functions.

The axon hillock is a specialized domain of the neuronal cell body from which the axon originates. A high amount of protein synthesis occurs in this region, as it contains a large number of Nissl granules (which are ribosomes wrapped in RER) and polyribosomes. Within the axon hillock, materials are sorted as either items that will enter the axon (like the components of the cytoskeletal architecture of the axon, mitochondria, etc.) or will remain in the soma. In addition, the axon hillock also has a specialized plasma membrane that contains large numbers of voltage-gated ion channels, since this is most often the site of action potential initiation.The survival of some sensory neurons depends on axon terminals making contact with sources of survival factors that prevent apoptosis. The survival factors are neurotrophic factors, including molecules such as nerve growth factor (NGF). NGF interacts with receptors at axon terminals, and this produces a signal that must be transported up the length of the axon to the nucleus. A current theory of how such survival signals are sent from axon endings to the soma includes the idea that NGF receptors are endocytosed from the surface of axon tips and that such endocytotic vesicles are transported up the axon.

is a British neuroscientist, and among the most highly cited researchers in the neurosciences. Until his retirement in 2017, he was a professor at Cardiff University and the founder and co-director of the Brain Repair Group, where he worked on developing cell therapies for neurodegenerative diseases including Parkinson's disease and Huntington's disease.

The superior colliculus (Latin, upper hill) is a paired structure of the mammalian midbrain. In other vertebrates the homologous structure is known as the optic tectum or simply tectum. The adjective form tectal is commonly used for mammals as well as other vertebrates.

The superior colliculus/optic tectum forms a major component of the midbrain. It is a layered structure, with a number of layers that varies by species. The layers can be grouped into the superficial layers (stratum opticum and above) and the deeper layers (the remaining layers). Neurons in the superficial layers receive direct input from the retina and respond almost exclusively to visual stimuli. Many neurons in the deeper layers also respond to other modalities, and some respond to stimuli in multiple modalities. The deeper layers also contain a population of motor-related neurons, capable of activating eye movements as well as other responses.The general function of the tectal system is to direct behavioral responses toward specific points in egocentric ("body-centered") space. Each layer contains a topographic map of the surrounding world in retinotopic coordinates, and activation of neurons at a particular point in the map evokes a response directed toward the corresponding point in space. In primates, the superior colliculus has been studied mainly with respect to its role in directing eye movements. Visual input from the retina, or "command" input from the cerebral cortex, create a "bump" of activity in the tectal map, which, if strong enough, induces a saccadic eye movement. Even in primates, however, the superior colliculus is also involved in generating spatially directed head turns, arm-reaching movements, and shifts in attention that do not involve any overt movements. In other species, the tectum is involved in a wide range of responses, including whole-body turns in walking rats, swimming fish, or flying birds; tongue-strikes toward prey in frogs; fang-strikes in snakes; etc.

In some vertebrates, including fish and birds, the tectum is one of the largest components of the brain. In mammals, and especially primates, the massive expansion of the cerebral cortex reduces the tectum ("superior colliculus") to a much smaller fraction of the whole brain. It remains nonetheless important in terms of function as the primary integrating center for eye movements.

Note on terminology: This article follows terminology established in the literature, using the term "superior colliculus" when discussing mammals and "optic tectum" when discussing either specific non-mammalian species or vertebrates in general.

Tinnitus is the hearing of sound when no external sound is present. While often described as a ringing, it may also sound like a clicking, hiss or roaring. Rarely, unclear voices or music are heard. The sound may be soft or loud, low pitched or high pitched and appear to be coming from one ear or both. Most of the time, it comes on gradually. In some people, the sound causes depression or anxiety and can interfere with concentration.Tinnitus is not a disease but a symptom that can result from a number of underlying causes. One of the most common causes is noise-induced hearing loss. Other causes include ear infections, disease of the heart or blood vessels, Ménière's disease, brain tumors, emotional stress, exposure to certain medications, a previous head injury, and earwax. It is more common in those with depression.The diagnosis of tinnitus is usually based on the person's description. A number of questionnaires exist that may help to assess how much tinnitus is interfering with a person's life. The diagnosis is commonly supported by an audiogram and a neurological examination. If certain problems are found, medical imaging, such as with MRI, may be performed. Other tests are suitable when tinnitus occurs with the same rhythm as the heartbeat. Rarely, the sound may be heard by someone else using a stethoscope, in which case it is known as objective tinnitus. Spontaneous otoacoustic emissions, which are sounds produced normally by the inner ear, may also occasionally result in tinnitus.Prevention involves avoiding loud noise. If there is an underlying cause, treating it may lead to improvements. Otherwise, typically, management involves talk therapy. Sound generators or hearing aids may help some. As of 2013, there were no effective medications. It is common, affecting about 10–15% of people. Most, however, tolerate it well, and it is a significant problem in only 1–2% of people. The word tinnitus is from the Latin tinnīre which means "to ring".

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